Injection pump and nozzle tester



Jan. 28, 1964 c. 1. TAYLOR 3,119,258

INJECTION PUMP AND NOZZLE TESTER Filed May 26, 1961 5 Sheets-Sheet 1 Inventor CECiL I. TAYLoR Attorneys 1964 c. l. TAYLOR INJECTION PUMP AND NOZZLE TESTER 5 Sheets-Sheet 2 Filed May 26, 1961 Inventor cEciL I TAYLOR B y M Home y 5 Jan. 28, 1964 v c. 1. TAYLOR INJECTION PUMP AND NOZZLE TESTER 5 Sheets- Sheet 3 Filed May 26, 1961 Inventor CECIL 1.TAYLOR Jan. 28, 1964 c. l. TAYLOR INJECTION PUMP AND NOZZLE TESTER Filed May 26, 1961 5 Sheets-Sheet 4 Invenlor CEcH. I. TAYLOR Attorney Jan. 28, 1964 c. l. TAYLOR 3,119,253

INJECTION PUMP AND NOZZLE TESTER Filed May 26, 1961 5 Sheets-Sheet 5 Invenlo'r dEc FL I. TAYLoR Altorrmxg United States Patent Ofi ice 3,319,253 Patented Jan. 28, 1964 3,119,258 INJECTION PUMP AND NOZZLE TESTER Cecil Isaac Taylor, Buckingham, England, assignor to Leslie Hartridge Limited, Buck ngham, England, a British company Filed May 26, li el, her. No. 113,933 15 Claims. (ill. 73-468) This invention has reference to improvements in and relating to apparatus for testing the fuel injection pumps and the injectors of compression ignition engines by a method in which the spray discharge from an injector under test or from a test injector supplied with liquid from a pump under test is exposed for visual examination, said apparatus being adapted to have a pump and an injector mounted on it and having means adapted to drive the pump cam shaft so that the pump supplies liquid under injection pressure to an injector, said apparatus including supply means for the liquid.

Apparatus according to the invention makes use of a novel method of exhibiting the spray from an injector for enabling various tests to be effected. That is to say when apparatus according to the invention is in use, spray from an injector under test, or spray from an injector supplied with liquid from a pump under test, is wholly submerged in a body of transparent liquid in a transparent receptacle or in a receptacle having a transparency in its Wall exposing the interior of the chamber to view, so that air contained in the spray (i.e., air contained in the liquid spray and brought out of solution in this liquid at the moment of spraying owing to the sudden release of pressure on the sprayed liquid as it emerges from the injector nozzle) becomes visible in the body of liquid substantially in the pattern of the spray; and in order that the released air shall not, by temporarily impairing the transparency of the body of liquid, prevent inspection of the spray for the duration thereof or prevent inspection of other sprays following the first spray in quick succession, the body of liquid is maintained under sufficient pressure to ensure that the air is dissolved in it almost immediately the air is brought out of solution in the sprayed liquid.

The specific volume of air in a saturated solution increases with pressure and, furthermore, turbulence in the fiuid considerably accelerates the rate at which a supersaturated solution will release air and the rate at which an unsaturated solution will absorb it. The test apparatus according to the invention, when in operation, contains liquid to be sprayed which is saturated with air at atmospheric pressure. When this liquid issues from the injector the divergence of the spray causes the pressure on the individual particles to be reduced, and because of the accompanying extremely high turbulence, the liquid liberates air rapidly. If the liquid is sprayed into a chamber having a connection to the atmosphere, the efflux from the outlet will contain unsaturated liquid mixed with free air. Now if the outlet from the chamber is restricted so that the pressure is held above atmospheric pressure, the ability of the liquid in the chamber to redissolve the air will be increased because its percentage saturation is reduced. If the pressure in the chamber is increased sutficiently the free air will dissolve almost immediately, leaving the liquid clear and transparent except for that which is actually issuing from the injector spray hole(s). Tests made up to the present do not show the pressure to be critical. A pressure of 20 to 30 pounds per square inch above atmospheric pressure has been found suitable and is given herein merely by way of non-limiting example. The pressure is also limited to permit of the escape of liquid sprayed into the container by the injector; and in any event it is desirable to keep the pressure in the receptacle low for reasons of safety.

The pattern of the submerged spray appears cleanly in the body of liquidin which it is confined-and there is a complete absence of fog and spray fumes in the vicinity of the apparatus.

The test apparatus in accordance with the invention comprises the above-mentioned receptacle which is closed to atmosphere save at a pressure relief device and an injector mounting adapted to support an injector with the delivery end of the nozzle thereof within the receptacle so as to be immersed in a body of liquid contained in the receptacle, said receptacle being transparent or comprising a transparent part and the pressure relief device being adapted to enable the body of liquid in the receptacle to reach a pressure such that air contained in liquid which is sprayed into the body of liquid within the container by an injector borne by the injector mounting and which is fed to the injector by the pump is dissolved in the said body of liquid almost immediately after the air has formed the pattern of the spray in the said body of liquid.

The invention also comprises apparatus as set forth in the immediately preceding paragraph provided with an electric lamp adapted when energised to illuminate the interior of the receptacle, means operated by the pump drive shaft adapted to bring about momentary energisation of the lamp at any one of a number of angular positions of the cam shaft of the pump, and means adapted to indicate the said angular position.

The pressure relief device or device for maintaining pressure in the receptacle may simply comprise a howrestricting orifice from the receptacle, and/ or a pressure operated valve. The orifice may be adjustable as to effective size.

The apparatus may have one transparent receptacle, necessitating connection of the pump stages of a multistage pump to the injector in succession when the pump is tested or it may have a number of receptacle with injectors adapted to be connected to the respective stages of a pump to be tested. The or each receptacle may be in a dark chamber having a viewing opening.

The receptacle(s) may be of cylindrical form or otherwise shaped so that the observed spray appears magnified by the body of liquid, and when the or each receptacle is viewed through a window or transparency in a dark chamber the window may be in the form of or may be covered by a magnifying lens. The or each receptacle may include a scale indicating the length and/or the width of the sprays produced therein. 7 j I As the apparatus is applicable to the testing and correct adjustment of pumps of various types the term stage used herein is a general term chosen to cover the term pump element, distributor point or the like. Thus, if a pump comprising a single cylinder and a distributor adapted to control the flow of fuel from the pump to six separate injectors be considered the pump will have six stages, each stage comprising a distributor point.

The invention will now be described with reference to the accompanying drawings wherein:

FIGURE 1 is a diagrammatic layout of the apparatus including a six stage pump P and an injector 1;

FIGURE 2 is a perspective view showing a casing 1 of opaque material such as metal containing a transparent receptacle 2, said casing providing a dark chamber in which the receptacle 2 can be seen through a window 3 in the casing and can be illuminated by a discharge lamp 4- in a housing 5 forming part of the casing, said casing being provided with a mounting 6 for an injector 1;

FIGURE 3 is a perspective view of an unhoused receptacle, indicated by 8, comprising a hollow transparent glass cylinder 9 closed at its top and bottom by plates 10 and 11 respectively. The plates 10 and '11 are clamped to the ends of the cylinder by bolts 12. Plate 16* carries 3 a mounting 13 for an injector I. A discharge lamp 14, with reflector 15, is arranged in front of the cylinder 9 so as to illuminate the contents thereof;

FIGURE 4 is a perspective view of one form of contact making mechanism comprising a single pair of contacts for controlling the illumination of the lamp in the test apparatus, this figure including a ring graduated in degrees for indicating the angular position of the pump cam shaft at any instant, as will be explained;

FIGURE 4A is a perspective view of a multi-contact disc for use in place of the single-contact disc shown in FIGURE 4;

FIGURE 5 is a perspective view of contact making mechanism (including a degree ring like that shown in FIGURE 4) wherein any one of a number of multi-contact discs each having contacts differing in number and angular spacing from the other discs can be selected for use in energising the lamp according to the number of pump stages in a pump under test;

FIGURE '6 is a perspective view of an inductive device for use in place of the contacts shown in FIGURE 4.

The apparatus shown in FIGURE 1 comprises a pump mounting and a shaft 21, which shaft drives the pump cam shaft through a coupling 22 and is driven by a belt and pulley 23 as shown or by any other suitable means. The pump driving shaft 21 carries an electric contact 24 at one end, said contact being rotatable with the shaft. A ring or scale 25 graduated in degrees and arranged coaxially of the shaft is borne by a disc which carries a counter contact 26 the disc and contact 26 being angularly adjustable in relation to the ring and the disc being turnable on the axis of the shaft but not being driven by the shaft. The two contacts momentarily make once in each revolution of the shaft. The contacts are in a circuit comprising a battery, amplifier A and a discharge lamp 27 so that each time the contacts make the lamp flashes. Liquid, supplied to the pump from a source not shown, is forced by any selected stage of the pump to the injector I at high pressure through a pipe 28, the injector being carried by a mounting 29.

The injector I dips at its nozzle end into a receptacle 30 which is transparent or is provided with a window or windows for admitting light to its interior and for enabling its interior to be seen. The receptacle is closed to atmosphere save at an outlet 31; it is charged with transparent liquid, in practice the same kind of liquid as that fed to the pump. When the lamp flashes the liquid in the receptacle is illuminated. The receptacle may be in or may comprise a dark chamber in order to render the spray pattern more clearly visible during moments of illumination.

The liquid used, both in the pump and in the receptacle, is conveniently oil of the kind normally used for testing compression ignition internal combustion engine pumps and injectors.

When the shaft 21 coupled to the pump cam shaft is rotating and the rack or the like control of the pump is appropriately operated the injector sprays liquid into the body of liquid in the receptacle once during each rotation of the shaft and the lamp is momentarily energised.

If it be desired to make a phase angle test the position of the contact 26 is adjusted around the axis of the shaft 21 until the momentarily energised lamp illuminates the successive spray patterns in the receptacle at the moment of commencement of each. The graduated ring 25 is then adjusted to zero in relation to an index, the ring and the contact 26 are then moved through an angle corresponding to the correct phase angle between the first and second stages of the pump, and No. 2 stage of the pump is connected to the injector. If the successive sprays illuminated by the lamp are just commencing the first and second stages are in phase; if said sprays are not just commencing at the moments of lamp illumination the contact 26 is displaced with the ring until illumination occurs at the moment of spray commencement and '4 the angle of this displacement, indicated by the graduated ring and the index, is the angle, plus or minus according to the direction of displacement, by which the No. 2 stage is out of phase with No. 1 stage. This procedure is repeated for the remaining stages of the pump, it being understood that adjustments are made for each stage to bring the stages into correct phase. Liquid equal in quantity to the injected liquid escapes through outlet 31 and a pipe 32 but the outlet includes a restriction so that there is some build up of pressure in the body of liquid in the receptacle as and for the purpose previously explained. Pipe 32 may lead to a flow measuring device such as a flowmeter or to a measuring flask.

Spray duration in terms of angle of cam shaft rotation is ascertained by setting the graduated ring to zero when the lamp illuminates the successive sprays at the moments of commencement of each, and then displacing the contact 26 and ring 25 until the sprays terminate after reaching their maximum intensity. The duration is indicated by the ring and the index--the indicated angle being the angle through which the pump shaft turns during each spraying period.

Spray fluctuations, if any, can be observed whilst the contact 26 is displaced through the angle of spray dura- .tion.

The lamp may if desired be detachably mounted in the apparatus and have a flexible lead for the purpose, for example, of enabling the hair line on the tappet of a single cylinder pump to be stroboscopically observed with respect to the usual reference mark in an opening in the pump case and the moment of commencement of an in-' jection as indicated by the spray, a condition readily asccrtainable by the present apparatus.

Other tests which can be carried out with the aid of the present apparatus will be readily apparent to those skilled in the art.

When a pump is tested the injector employed is a test or master injector; when an injector is tested the pump employed is a test or master pump.

Examples of receptacles for use in the present ap-' paratus will now be further described with reference to FIGURES 2 and 3.

The window 3, FIGURE 2, is of plano-convex form so as to give magnification of the spray patterns formed in liquid in the receptacle. The receptacle is mounted at its base on a suitable support 35 in the apparatus. The outlet for excess liquid is indicated by 36 and the pipe for conveying the excess liquid to a desired point is indicated by 37, said outlet being restricted to ensure the required pressure build up in the receptacle.

In FIGURE 3 plate 10 has the restricted outlet indi cated by 38, for excess liquid and the pipe 37 comparable with pipe 37, FIGURE 2. The receptacle is mounted in the apparatus by attaching the plate 10 to a support 39 whilst the lamp 14 and reflector 15 are borne by a sup port 40 in the apparatus. The injector I is set behind the axis of the cylinder 9 to ensure magnification of the spray pattern by the body of liquid in the cylinder.

The graduated ring or scale and contacts described with reference .to FIGURE '1 may be as shown in FIGURE 4. The graduated ring 25, FIGURE 4, frictionally engages the periphery of a disc 41 turnably mounted in the apparatus; it and the disc can be turned together by an operators rotating by handle 42 a pulley 43 connected to ring 25 by a belt 44; the disc carries the contact 26 so that when the ring is turned the contact turns with it unless the contact is deliberately held against movement. The index for the ring is indicated by 2511, said index being fixed to a convenient part of the apparatus.

The single rotary contact 24 may, if desired, be replaceable by a group of equi-angularly spaced contacts 45, as shown in FIGURE 4A, the contacts as numerous as the stages of a pump to be tested. The said group of contacts is borne by a disc 46 which, like the disc 47 carrying the contact 24 in FIGURE 4,

is removably mounted on the shaft 21, against a flange portion 62 on the shaft, with the aid of a fly nut 48, a dowel on the flanged port-ion 62 accurately locating the disc 46 or 47 thereon by engagement with a hole as in the selected disc. Alternatively, a single contact 26a, FIGURE and a number of axially spaced groups of rotary contacts 5%) on discs 51 may be employed, the contacts in each group being equally spaced around t .e peripheries of the discs 51 and each group having contacts different in number from any other group. The contact 26a is on a carrier 52 slidable on a bar 53 parallel with the axis of rotation of the contacts so that the said contact can be located to co-operate with any selected group of contacts 582. The bar 53 is racked at 54 to facilitate location of the contact 26a in relation to the selected group of contacts, the contact being locked in selected position by a thumb screw 55. Discs 51 are secured to the shaft 21 by a nut 56. Bar 51% is rigidly carried by disc 41, FIGURE 5, and the disc rotatably carries the ring 25 so that the ring can, when necessary, be zeroised in relation to an index like index 215a, FIGURE 4-.

Inductively controlled means for bringing about energisation of the lamp may be used in place of contacts. One such means is shown in FlGURE 6 where an inducance coil S 7is used in place of contact 2 and discs 58 with groups of iron projections 5d, comparable in arrangement with the groups of contacts 5%, FlGURE 5, are used in place of the said groups of contacts. The current induced every time a projection passes the core of the coil is suitably amplified and the amplified current energises the lamp. The coil is on a carrier as borne by a racked bar at comparable with the carrier 52 and racked bar 53, respectively. FlGURE 5. It will be understood that a coil like 5'? may replace the contact 26 FlGURE 1 whilst a disc with a single projection, like one of the projections 59, or a disc with a number of such projections may replace the discs 47, as, 'EiGURES 4 and 4A respectively.

Apparatus provided with multiple rotary contacts are described, or with a coil and a disc or discs having multiple projections and a number of receptacles and injectors, each receptacle being adapted to be momentarily illuminoted by a lamp, may be used to enable the sprays from successive pump stages to be observed in rapid continuous succession. in such cases the graduated ring need only be marked through a range of about 15 each side of a zero marl; since an injection and lamp illumination will occur every time a contact 55} or a projection 55" on the selected disc 51 or 53 engages contact 26.21 or energises coil 57, the pump stages being connected to injectors dipping into the respective receptacles.

I claim:

'1. Apparatus for testing fuel injection pumps and injectors of compression ignition internal combustion engines which includes a mounting and a driving shaft for a fuel injection pump and means to supply liquid to a fuel injection pump when mounted in the apparatus, comprising a receptacle closed to the atmosphere to contain a body of liquid, pressure relief means connected to said receptacle, an injector mounting adapted to support an injector with the delivery end of the nozzle thereof within said receptacle so as to be immersed in the body of liquid contained in said receptacle, said receptacle being at least in part transparent to enable said body of liquid to be seen, and said pressure relief means being set to enable said body of liquid in said receptacle to attain a pressure such that air released from liquid which is sprayed into said body of liquid through said injector is dissolved in said body of liquid immediately after said air has made visible the pattern of said spray.

2. Apparatus as claimed in claim 1 comprising a plurality of receptacles and injectors equal to the number of stages in said fuel injection pump, the injectors in said receptacles being respectively connected to the individual outlets of said fuel injection pump.

3. Apparatus as claimed in claim "1 wherein said receptacle is a dark chamber provided with a transparent window for viewing the spray pattern in said receptacle.

4. Apparatus as claimed in claim 3 wherein said window is provided with a magnifying lens.

5. Apparatus as claimed in claim 3 wherein said window is so shaped that said spray is magnified by said body of liquid in said receptacle.

6. Apparatus as claimed in claim 1 wherein said receptacle includes a scale for indicating at least one dimention of said pattern of said spray produced in said body of liquid.

7. Apparatus as claimed in claim 1 wherein said pressure relief means comprises mews adapted for connection to means for measuring the amount of liquid escaping through said pressure relief means.

8. Apparatus as claimed in claim 1 comprising an electric lamp adapted when energised to illuminate the interior of said receptacle, means operated by said pump driving means adapted to bring about momentary energization of said lamp at at least one rotary position of said pump driving shaft, and means for indicating said rotary position.

9. Apparatus as claimed in claim 8 wherein said lamp is detachably mounted in said apparatus and is connected by a flexible lead.

10. Apparatus for testing fuel injection pumps and injectors of compression ignition internal combustion engines which includes a mounting and driving shaft for a fuel injection pump and means for supplying liquid to a fuel injection pump when mounted in the apparatus, comprising a receptacle closed to atmosphere to contain a body of liquid, said receptacle being made of opaque material and including a window through which the interior of said receptacle may be viewed, pressure relief means for maintaining the pressure of said body of liquid in said receptacle at a desired pressure above atmospheric pressure, an injector mounting on said receptacle to support an injector with the end of the nozzle thereof within said receptacle so that its delivery end is immersed in said body of liquid, whereby air dissolved in the liquid sprayed through said nozzle into said body of liquid is brought out of solution by the sudden release of pressure in said spray and is at once redissolved in said body of liquid so that the pattern of said spray becomes momentarily visible, a lamp to illuminate said spray, electrical means operated in synch ronism with the rotation of said pump driving shaft for momentary energising said lamp to make said spray pattern visible through said transparent window, and means to indicate the rotational position or" said pump driving shaft at the instant when said lamp is energised.

11. Apparatus as claimed in claim 10 comprising a plurality of receptacles and injectors equal to the number of stages in said fuel injection pump, the injectors in said receptacles being respectively connected to the individual outlets of said fuel injection pump.

12. Apparatus as claimed in claim 10 wherein said lamp is detachably mounted in said apparatus and is connected by a flexible lead.

13. Apparatus as claimed in claim 10 wherein said means to energise said lamp comprises at least one contact rotatable in synchronism with said pump driving shaft and a co-operating contact adapted momentarily to be engaged by said one contact once in each revolution of said pump driving shaft, and said means adapted to indicate the rotational position of said shaft at the moment of lamp energisation comprises a circular gradu! ated scale and a co-operating fixed index, said scale being manually rotatable for setting about the axis of rotation of said one contact and said co-operating contact being movable with said scale.

14. Apparatus as claimed in claim 13 comprising at least one group of rotatable contacts adapted to engage said co-operating contact momentarily in succession, each contact of said group engaging said co-operating contact once in each revolution of said pump driving shaft.

15. Apparatus as claimed in claim 14 comprising a plurality of groups of rotatable contacts, each group containing a difierent number of rotatable contacts from any other group, said groups being spaced from each other along the axis of said pump driving shaft, and said co-operating contact being adjustably mounted so that it may be moved into operative relationship with any selected group.

16. Apparatus as claimed in claim 10 wherein said means to energise said lamp comprises at least one magnetic member rotatable in synchronism With said pump driving shaft and a co-operating magnetic core carrying a winding so positioned that said magnetic member passes close to said core to induce a pulse of electric current in said winding during each revolution of said pump driving shaft, and means controlled by said current pulses to supply energising pulses to said lamp.

17. Apparatus as claimed in claim 16 comprising at least one group of rotatable magnetic members adapted successively to induce pulses of current in said winding,

References Cited in the file of this patent UNITED STATES PATENTS 2,470,351 Hartridge May 17, 1949 2,629,255 Hartridge Feb. 24, 1953 2,858,611 Morse Nov. 11, 1958 FOREIGN PATENTS 620,637 Great Britain Mar. 28, 1959 

1. APPARATUS FOR TESTING FUEL INJECTION PUMPS AND INJECTORS OF COMPRESSION IGNITION INTERNAL COMBUSTION ENGINES WHICH INCLUDES A MOUNTING AND A DRIVING SHAFT FOR A FUEL INJECTION PUMP AND MEANS TO SUPPLY LIQUID TO A FUEL INJECTION PUMP WHEN MOUNTED IN THE APPARATUS, COMPRISING A RECEPTACLE CLOSED TO THE ATMOSPHERE TO CONTAIN A BODY OF LIQUID, PRESSURE RELIEF MEANS CONNECTED TO SAID RECEPTACLE, AN INJECTOR MOUNTING ADAPTED TO SUPPORT AN INJECTOR WITH THE DELIVERY END OF THE NOZZLE THEREOF WITHIN SAID RECEPTACLE SO AS TO BE IMMERSED IN THE BODY OF LIQUID CONTAINED IN SAID RECEPTACLE, SAID RECEPTACLE BEING AT LEAST IN PART TRANSPARENT TO ENABLE SAID BODY OF LIQUID TO BE SEEN, AND SAID PRESSURE RELIEF MEANS BEING SET TO ENABLE SAID BODY OF LIQUID IN SAID RECEPTACLE TO ATTAIN A PRESSURE SUCH THAT AIR RELEASED FROM LIQUID WHICH IS SPRAYED INTO SAID BODY OF LIQUID THROUGH SAID INJECTOR IS DISSOLVED IN SAID BODY OF LIQUID IMMEDIATELY AFTER SAID AIR HAS MADE VISIBLE THE PATTERN OF SAID SPRAY. 